Make openRecord_l more like createTrack_l for fast tracks: part 3

Create the callback thread earlier, before creating the IAudioRecord,
so that the thread's tid is available as a parameter to openRecord().

Also move initialization of mCbf to same point as in AudioTrack.cpp.

Change-Id: I61ea4c5e2724ccfc691aaf51bc02a7c10d5a7495